Pilot Debrief

BRANTLY B-2B near East Troy, WI — 2010-07-04

Final reportCEN10CA371
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Date
2010-07-04
Location
East Troy, WI, USA
Airport
57C
Aircraft
BRANTLY B-2B
Registration
N9011R
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Hover

Probable cause

The pilot's failure to maintain control during landing.

NTSB narrative

The helicopter pilot performed a straight-in autorotation to runway 18 for a rotor rpm check. The engine rpm began to rapidly increase and the pilot rolled the throttle completely off and lowered collective. He reported that the left skid was coming off the ground and he applied full left cyclic and full down collective. The aircraft teetered and continued to roll right. The pilot stated that the helicopter had an articulated landing gear system. He said that the struts travel approximately seven to eight inches and “if only one side retracts it causes a ‘rolling moment’.” About 22 minutes before the accident, the recorded winds about seven nautical miles and 155 degrees from the accident site were 200 degrees at 14 knots with gusts to 32 knots. An examination of the accident helicopter’s controls and landing gear revealed no preexisting anomalies.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have aborted the maneuver before entering hover.

NTSB coding

Evidence available

  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

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